Patent attributes
Crowdsourcing systems with machine learning are described, for example, to aggregate answers to a crowdsourced task in a manner achieving good accuracy even where observed data about past behavior of crowd members is sparse. In various examples a machine learning system jointly learns variables describing characteristics of both individual crowd workers and communities of the workers. In various examples, the machine learning system learns aggregated labels. In examples learnt variables describing characteristics of an individual crowd worker are related, by addition of noise, to learnt variables describing characteristics of a community of which the individual is a member. In examples the crowdsourcing system uses the learnt variables describing characteristics of individual workers and of communities of workers for any one or more of: active learning, targeted training of workers, targeted issuance of tasks, calculating and issuing rewards.